Global shipments of mobile phones rose 40% in the first half of the year, according to new figures.
Motorola has performed strongly in Central and Latin America
The industry continues to enjoy buoyant growth, analysts Strategy Analytics reported, with shipments for the whole of 2004 forecast to reach new highs.
Samsung benefited most, boosting its second quarter market share from 10.5% to 14.4%. But market leader Nokia saw its share fall from 36% to 28.9%.
Strategy Analytics said it expected 670m handsets to be shipped this year.
A total of 157m handsets were shipped worldwide in the second quarter, representing year-on-year growth of 38%.
This was down slightly from the first quarter, when shipments rose 42%.
Four of the world's six largest manufacturers increased their total sales by more than 50% during the second quarter, boosted by sales in developing markets.
Motorola, the world's second largest handset manufacturer, increased its shipments by 53% while its market share rose from 13.9% to 15.4%.
SEMC and LG also increased share although German manufacturer Siemens saw its share drop from 7.1% to 6.6%.
Heavy price-cutting in the mobile phone sector has taken its toll this year with Nokia suffering a 5% fall in second quarter sales.
Strategy Analytics said the Finnish firm had cleared an estimated 3m surplus handsets in the first quarter of the year and had begun to stabilize its business.
"Second quarter growth continued at a healthy clip due to surging device replacement in developed markets and vigorous net subscriber growth in developing regions, particularly Central and Latin America," said analyst Neil Mawston.
Mr Mawston upgraded his forecasts for full year shipments from 586m to 670m, but warned that component shortages could potentially disrupt sales in the final quarter.
Global shipments totalled 320m in 2003.
Separately, shipments of personal digital assistants rose 12% in the second quarter, following ten consecutive quarterly declines.
According to preliminary estimates produced by Gartner Inc, shipments totalled 2.75m units over the period.
The growth was fuelled by a 289% quarterly rise in shipments of Research In Motion's BlackBerry model.
PalmOne retained its leadership of the market, according to Gartner, although its share fell from 38.5% to 33.2%.